Display system, display device, display terminal, display method of display terminal, and control program

ABSTRACT

Since a display device is used in a relatively large room, it often displays images on a large screen. On the other hand, a display terminal often displays images on a small screen. Therefore, when the same image is displayed on the display device and the display terminal, the displayed image on the display terminal is so small that the viewer has difficulty in discerning details of the image, which poses a problem that the display terminal is disadvantageous. In a display system including a display terminal and a display device, the display device detects position coordinates optically pointed out by a pointer on a displayed image, and displays a given pointer mark at the detected position coordinates. The display terminal displays a magnified version of the displayed image approximately around received position coordinates serving as a center thereof, and displays a given pointer mark at the position coordinates.

TECHNICAL FIELD

The present invention relates to a display system in which a pluralityof display terminals and display devices perform video display incooperation with one another.

BACKGROUND ART

In recent years, a system or apparatus in which a plurality of displaydevices and display terminals perform video display in cooperation withone another has been widespread in the fields of video education andpresentation. Patent Document 1 is one of techniques for such a videosystem. Patent Document 1 discloses that a movable pointer graphic isdisplayed on a lecture material on a terminal of a lecturer, and thesame action as that made by the pointer graphic on the lecture materialon the terminal of the lecturer is reproduced in real time on a lecturematerial displayed on a terminal of a participant.

RELATED ART DOCUMENTS Patent Documents

Patent Document 1: Japanese Patent Application Laid-Open Publication No.2004-32582

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

A presentation system for making a product presentation or the like bythe use of one display device with a large screen such as a projectorand display terminals distributed to individual viewers has been known.Such a presentation system poses a problem that, when the same image isdisplayed on the display device and the display terminals, the displayedimage on the display terminals is so small that the viewer hasdifficulty in discerning detailed parts of the image.

Also, even if the display terminal has a magnifying function, just apart of an original image is displayed when the image is magnified.Therefore, when the image is magnified, the part of the image which theuser intends to see is not always displayed, and it takes a lot oftrouble to find the intended part of the magnified image on display,which leads to a problem of a lack of handiness.

Means for Solving the Problems

In order to solve the problems mentioned above, a display system of thepresent invention includes a display terminal that displays first imagedata and a display device that displays second image data in conjunctionwith the display terminal, display contents of the first image datainclude contents of a partial area of display contents of the secondimage data, and a pointer mark of the display terminal is displayed atan image position of the first image data that corresponds to an imageposition of the second image data at which a pointer mark of the displaydevice is displayed.

Furthermore, according to the display system of the present invention,when the image position of the pointer mark displayed on the displaydevice is shifted, the first image data displayed on the displayterminal is changed.

Effects of the Invention

An object of the present invention is to provide a handy display system.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is a configuration diagram of an example of an overall displaysystem;

FIG. 2 is a configuration diagram of a display device;

FIG. 3 is a configuration diagram of a display terminal;

FIGS. 4( a)-4(c) depict examples in which a display image and a pointermark are displayed in the display terminal;

FIG. 5 is a flowchart showing an operation of the display device;

FIG. 6 is a flowchart of a main operation of the display terminal;

FIG. 7 is a flowchart showing an operation in a data selection mode;

FIG. 8 is a flowchart showing an operation in a data display mode;

FIG. 9 is a flowchart showing an operation in a pointer display mode;

FIGS. 10( a)-10(f) depict examples of images displayed on the displayterminal and the display device;

FIG. 11 is a flowchart of an operation in the pointer display modeaccording to a second embodiment;

FIGS. 12( a)-12(f) depict examples of images displayed on the displayterminal and the display device according to the second embodiment;

FIG. 13 is a flowchart of an operation in the pointer display modeaccording to a third embodiment;

FIGS. 14( a)-14(g) depict examples of images displayed on the displayterminal and the display device according to the third embodiment;

FIG. 15 is a flowchart showing an operation of the display deviceaccording to a fourth embodiment;

FIG. 16 is a flowchart of a main operation of the display terminalaccording to the fourth embodiment;

FIG. 17 is a flowchart showing an operation in a pointer transmissionmode according to the fourth embodiment;

FIGS. 18( a)-18(d) depict examples of images displayed on the displayterminal and the display device according to the fourth embodiment;

FIGS. 19( a)-19(c) depict examples of images displayed on the displayterminal and the display device according to a fifth embodiment;

FIGS. 20( a)-20(e) depict examples of images displayed on the displayterminal and the display device according to a sixth embodiment; andFIGS. 21( a)-21(d) depict examples of images displayed on the displayterminal and the display device according to a seventh embodiment.

EMBODIMENTS

Embodiments of the present invention will be described below withreference to drawings.

First Embodiment

Hereinafter, specific embodiments of a display system according to thepresent invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram of an example of the overall displaysystem of the present invention. A display system 400 includes displayterminals 100A, 100B, and 100C connected to a network 300, and a displaydevice 200. Although FIG. 1 depicts three display terminals 100 and onedisplay device 200 included in the display system 400, the numbers ofthe display terminals and display devices are not limited thereto, andany numbers may be adopted as long as the numbers are one or more.

The display system 400 is used for, for example, meetings, lectures,presentations, and the like. The display device 200 is, for example, aprojection display device such as projector, and it projects a displayimage 251 on a large screen 252. Participants are thus able to view theprojected image 251 concurrently. Also, each display terminal 100 has adisplay unit 102 and a display image 151 is displayed on the displayunit 102. Hence, users of the display terminals 100 are able toseparately view the display image 151.

The display terminals 100 and the display device 200 are connected tothe network 300 through radio communication, respectively. The network300 is, for example, LAN (local Area Network), and communication withthe network 300 is established through a wireless LAN of, for example,IEEE802.11a/b/n.

The display terminal 100A is used as a host terminal in the displaysystem 400, and the other display terminals 100B and 100C are used asclient terminals. The display terminal 100A serving as the host terminalconverts selected display data into image data, displays the image dataas a display image 151A on its own display unit 102A, and transmits theimage data to the display device 200 through the network 300.

The display device 200 displays the image data received from the displayterminal 100A through the network 300, as the display image 251. Apointer 260 is, for example, a laser pointer that emits laser light ontothe screen to optically point out an arbitrary position on the displayimage 251. A presenter uses the pointer 260 when explaining the contentsof the display image 251. The display device 200 is provided with asensor unit (not depicted) having a function of detecting a position(coordinates)) pointed out by the pointer 260. Coordinates thus detectedwill hereinafter be referred to as pointer coordinates. The displaydevice 200 displays a pointer mark 250 at the position corresponding tothe pointer coordinates in a superposed manner on the display image 251,thereby emphatically indicating the position pointed out by the pointer260. Furthermore, the display device 200 transmits the pointercoordinates to the display terminals 100A, 100B, and 100C through thenetwork 300.

In place of the pointer mentioned above, the display device 200 may havea pointer mark generating function so as to display a pointer mark onthe display image 251 and transmit the pointer coordinates to thedisplay terminals 100A, 100B, and 100C.

Also, the display terminal 100A transmits display data to the displayterminals 100B and 100C serving as client terminals. The displayterminals 100B and 100C convert the received display data into imagedata and display the image data as display images 151B and 151C on theirown display units 102B and 102C. In this manner, the users are able tocheck the contents of the display image 251 projected on the screen 252by the display device 200, by viewing the display units 102B and 102C ofthe display terminals which the users have at hand.

When the display terminal 100 receives data of pointer coordinates fromthe display device 200, the display terminal 100 displays a pointer mark150 at the position corresponding to the pointer coordinates in asuperposed manner on the display image 151. As a result, the user isable to check a position pointed out on the display image 251 by thepointer 260, by viewing the display unit 102 on hand.

Also, the display terminal 100 has a demagnifying button 152, an overalldisplay button 153, and a magnifying button 154. When the magnifyingbutton 154 is selected, the display image 151 is changed to a magnifiedversion of image data. If the magnifying button 154 is selected when themagnified image data is on display, the display image 151 is furthermagnified. In this manner, the magnification scale of the display image151 may be increased every time the magnifying button 154 is selected.The overall view of the image data can be displayed any time byselecting the overall display button 153 when the magnified image datais on display. Also, when the demagnifying button 152 is selected, thedisplay image 151 is changed to a demagnified version of the image data.If the demagnifying button 152 is selected when the demagnified imagedata is on display, the display image 151 is further demagnified. Inthis manner, the magnification scale of the display image 151 may bereduced every time the demagnifying button 152 is selected.

The display image 251 is displayed on a large screen of, for example,200 inches, while the display unit 102 of the display terminal 100 is asmall screen of, for example, 10 inches. Therefore, when the whole imagedata is displayed on the display unit 102, the resulting image may be sosmall that its detailed contents are difficult to see. In such a case,by selecting the magnifying button 154 to display a magnified version ofthe image, the detailed contents of the image can be checked. However,just a part of the image data is displayed on the display unit 102 whenthe image is magnified. Therefore, when the image is magnified, the partof the image which the user intends to see is not always displayed. Tosolve this problem, the display system of the present invention displaysa magnified image so that the pointer mark 150 is located at theapproximate center of the image. Hereinafter, the configuration andoperation of each device will be described in detail.

FIG. 2 is a configuration diagram of the display device 200. The displaydevice 200 includes a control unit 201, a display unit 202, a sensorunit 203, a memory 204, an operation unit 205, a communication unit 206,a connection unit 207, a sound input unit 208, and a sound output unit209, which are interconnected via a system bus 220.

The control unit 201 is, for example, a microprocessor that performsoverall control for the display device 200. The system bus 220 is a datacommunication path for data transmission/reception between the controlunit 201 and other component units in the display device 200. Thedisplay unit 202 is, for example, a liquid crystal projector thatprojects and displays an image on the screen 252. The sensor unit 203is, for example, a camera that takes the display image 251 and appliesimage processing to the taken image by the control unit 203, therebydetecting the pointer coordinates representing a position (coordinates)pointed out by the pointer 260.

The memory 204 is, for example, a rewritable memory such as flashmemory. The memory 204 stores basic operation programs for the displaydevice 200 of the embodiment such as an operating system and givenapplication programs. It is presupposed that the version and functionsof the basic operation programs are upgraded by updating the programsstored in the memory 204. The memory 204 also records data and others.

The operation unit 205 receives various instructions from the user andhas various operation buttons such as a power button. The communicationunit 206 is an interface connected to the network 300 through radiocommunication such as the wireless LAN as described above. Theconnection unit 207 is an interface connected to other devices such asthe display terminal 100, and it transmits and receives data to and fromthe other connected devices. The sound input unit 208 is, for example, amicrophone to which audio signals are input.

The sound output unit 209 is, for example, a speaker that outputs audiosignals. After image data received from other devices through thecommunication unit 107 is stored in the memory 204 and is subjected toimage processing by the control unit 201, the image data is projected bythe display unit 202, thereby displaying the display image 251 on thescreen 252. At this time, when an audio signal is received, the audiosignal is subjected to sound processing by the control unit 201 and isoutput from the sound output unit 209.

FIG. 3 is a configuration diagram of the display terminal 100. Thedisplay terminal 100 includes a control unit 101, a display unit 102, amemory 103, an operation unit 104, a storage 105, a camera 106, acommunication unit 107, a connection unit 108, a sound input unit 109,and a sound output unit 110, which are interconnected via a system bus120.

The control unit 101 is, for example, a microprocessor that performsoverall control for the display terminal 100. The system bus 120 is adata communication path for data transmission/reception between thecontrol unit 101 and other component units in the display terminal 100.The display unit 102 is a display device such as a liquid crystaldisplay or organic EL display. The memory 103 is, for example, arewritable memory such as flash memory. The memory 103 stores basicoperation programs for the display terminal 100 of the embodiment suchas an operating system and given application programs. It is presupposedthat the version and functions of the basic operation programs areupgraded by updating the programs stored in the memory 204. The memory204 also records data and others.

On the display surface of the display unit 102, a touch panel thatfunctions as the operation unit 104 is provided. The operation unit 104is touched with the finger tip, touch pen or the like, and detects andtransmits the touched position to the control unit 101. For example, bydisplaying a menu such as a list of operation commands on the displayunit 102 and touching an operation command selected from the list by theuser, the touched position is detected, thereby inputting the variousoperation commands. The demagnifying button 152, overall display button153, and magnifying button 154 are selected by displaying button iconson the display unit 102 and touching the positions of the button icons.

The storage 105 is an information memory medium such as a memory card.The camera 106 takes still images and moving images, and data of imagestaken by the camera is stored in the memory 103 or storage 105. Thecommunication unit 107 is an interface connected to the network 300through radio communication. The connection unit 108 is an interfaceconnected to other devices, and it transmits and receives data to andfrom the other connected devices . The sound input unit 109 is, forexample, a microphone to which audio signals are input. The sound outputunit 110 is, for example, a speaker that outputs audio signals.

The display terminal 100A serving as the host terminal transmits displaydata selected from data stored in the memory 103A or storage 105A fromthe communication unit 107A through the network 300 to the displayterminals 100B and 100C serving as the client terminals. Also, thedisplay terminal 100A converts the display data into image data byapplying image processing thereto by the control unit 101A and displaysthe image data on its own display unit 102A as the display image 151A.Furthermore, the display terminal 100A transmits the image data to thedisplay device 200 from the communication unit 107A through the network300. At this time, the display terminal 100A stores the display data andimage data in the memory 103A.

In the display device 200, the image data received by the communicationunit 206 is stored in the memory 204, is subjected to image processingby the control unit 201, and is then projected on the screen 252 todisplay the display image 251. Also, in the display terminal 100Bserving as the client terminal, the display data received by thecommunication unit 107B is subjected to image processing by the controlunit 101B to be converted into image data and is displayed on thedisplay unit 102B as the display image 151B. At this time, the displaydata and image data are stored in the memory 103B. Also in the displayterminal 100C, the same operation as that in the display terminal 100Bis carried out.

Also, when pointer coordinates from the display device 200 are receivedby the communication unit 107, the pointer mark 150 is displayed at theposition corresponding to the pointer coordinates in a superposedmanner. In this state, when the demagnifying button 152 or themagnifying button 154 is selected, the image is displayed at a reducedor increased magnification scale approximately around the pointer mark150 serving as the center thereof. Note that, when the pointercoordinates are received, the image may be automatically displayed inits magnified form approximately around the pointer mark 150 serving asthe center thereof at the same time as the displaying of the pointermark 150. This mode for automatically displaying the magnified imagewill hereinafter be referred to as automatic magnification mode.

Whether or not the display terminal 100 is set to the automaticmagnification mode is determined in advance by the user through theselections on a menu displayed on the display unit 102.

FIG. 4 depicts examples in which the display terminal 100 displays thedisplay image 152 and the pointer mark 150 on the display unit 102. FIG.4( a) depicts an example of display of the whole image data(magnification scale=1), and FIG. 4( b) depicts an example of display ofa magnified version of the image data approximately around the positionof the pointer mark 150 serving as the center thereof. In this example,the control unit 101 creates the image data through the image processingof magnifying the display data and extracting an image of a proper sizethat can be displayed on the display unit 102 approximately around thepointer coordinates serving as the center thereof.

The display terminal 100 displays the created image data as the displayimage 151 on the display unit 102, and displays the pointer mark 150 atthe position corresponding to the pointer coordinates in a superposedmanner. When the magnifying button 154 is selected in the state of FIG.4( a) where the whole image data is displayed, the image is magnifiedapproximately around the pointer mark 150 serving as the center thereofas shown in FIG. 4( b). Also, when the display terminal 100 is set tothe automatic magnification mode, upon reception of the pointercoordinates, the display image 152 magnified approximately around thepointer mark 150 serving as the center thereof is automaticallydisplayed as shown in FIG. 4( b).

FIG. 4( c) depicts the image given by horizontally scrolling themagnified image of FIG. 4( b) while maintaining its magnification scale.Obviously, the image may be scrolled further horizontally, vertically,or diagonally. When the overall display button 153 is selected in thestates of FIGS. 4( b) and 4(c) where the magnified image is displayed,the whole image data as shown in FIG. 4( a) is displayed.

FIG. 5 is a flowchart showing an operation of the display device 200. Itis presupposed that the process flow indicated by this flowchart startsfrom a step of turning on a power supply. First, it is determinedwhether the communication unit 206 has received image data transmittedfrom a different device (display terminal 100A in this case) through thenetwork 300 (step S501). When the communication unit 206 has failed toreceive image data, the flow proceeds to step S504 to be describedlater. When the communication unit 206 has received image data at stepS501, the image data is stored in the memory 204 (step S502).

The image data is subjected to image processing by the control unit 201,and the display unit 202 then projects and displays the processed imagedata on the screen 252 as the display image 251 (step S503).Subsequently, the sensor unit 203 detects a position (pointercoordinates) pointed out on the display image 251 by laser light emittedfrom the pointer 260 (step S504). In this case, for example, the displayimage 251 is taken with a camera or the like. The image data captured bythe camera is stored temporarily in the memory 204, and only thespecific wavelength of laser light emitted from the pointer 260 isextracted from the image data, thereby detecting the position pointedout by the pointer 260.

When the pointer position is detected, the pointer coordinatesrepresenting the pointer position are transmitted from the communicationunit 206 to each display terminal 100 through the network 300 (stepS505). The pointer mark 250 is then displayed on the display image 251at the position corresponding to the pointer coordinates in a superposedmanner (step S506). After the pointer mark 250 is displayed, the flowreturns to step S501 and repeats the process flow therefrom. Also whenthe position pointed out by the pointer 260 is not detected at stepS504, the flow returns to step S501 and repeats the process flowtherefrom.

FIG. 6 is a flowchart of a main operation of the display terminal 100.It is presupposed that the process flow indicated by this flowchartstarts from a step of turning on a power supply. It is first determinedwhether a data selection mode is set (step S601). The data selectionmode is the mode executed by the display terminal 100A serving as thehost terminal, and the data selected here (referred to as display data)corresponds to data of the display image 251 displayed by the displaydevice 200. When the data selection mode is set, a process flow for thedata selection mode is carried out (step S602). The details of the dataselection mode will be described later. When it is determined at stepS601 that the data selection mode is not set, the process flow for thedata selection mode is not carried out and the flow proceeds to stepS603.

Next, it is determined whether the communication unit 107 has receiveddisplay data from a different device (step S603). When the communicationunit 107 has received the display data, a process flow for a datadisplay mode is carried out (step S604). The details of the data displaymode will be described later. When it is determined at step S603 thatthe communication unit 107 has not received the display data, theprocess flow for the data display mode is not carried out and the flowproceeds to step S605.

Subsequently, it is determined whether the communication unit 107 hasreceived the data of pointer coordinates from the display device (stepS605). When the communication unit 107 has received the data of pointercoordinates, a process flow for a pointer display mode is carried out(step S606), and the flow returns to the first step S601. The details ofthe pointer display mode will be described later. Note that, when it isdetermined at step S605 that the communication unit 107 has not receivedthe data of pointer coordinates, the process flow for the pointerdisplay mode is not carried out, and the flow returns to step S601.

Operations executed in the data selection mode (step S602), the datadisplay mode (step S604), and the pointer display mode (step S606) willhereinafter be described in detail.

FIG. 7 is a flowchart showing an operation in the data selection mode.As described above, the process flow indicated in this flowchartrepresents the operation executed by the display terminal 100A servingas the host terminal.

First, data to be projected and displayed by the display device 200 isselected (step S601). In this step, a list of data stored in the memory103 or the storage 105 is displayed on the display unit 102 (step S701)and a desired data (display data) is selected from the list (step S702).The selected display data is stored in the memory 103 (step S703), andis then transmitted from the communication unit 107 to a differentdisplay terminal 100 through the network 300 (step S704).

Subsequently, the display data is converted into image data throughimage processing by the control unit 101 (step S705), and the image datais also stored in the memory 103 (step S706). Then, the image data isdisplayed on the display unit 102 (step S707) and is transmitted fromthe communication unit 107 to the display device 200 through the network300 (step S708), and the flow returns to the main operation process flowof FIG. 6.

The display terminal 100 that has received the display data transmittedthereto at step S704 proceeds from step S603 to step S604, and the datadisplay mode described later is set thereto as shown in FIG. 6. Thedisplay device 200 that has received the image data transmitted theretoat step S708 stores the image data in the memory 204 (step S502) andprojects and displays the image data as the display image 251 (stepS503) as shown in FIG. 5.

FIG. 8 is a flowchart showing an operation in the data display mode. Theprocess flow indicated by this flowchart represents the process executedby the display terminals 100B and 100C that have received the displaydata transmitted from the display terminal 100A serving as the hostterminal (step 5704 in FIG. 7).

When the communication unit 107 has received the display datatransmitted through the network 300, the display terminal 100 convertsthe display data into image data through image processing by the controlunit 101 (step S801). The display terminal 100 stores the convertedimage data in the memory 103 (step S802) and displays the image data onthe display unit 102 as the display image 151 (step S803), and the flowreturns to the main operation process flow of FIG. 6.

FIG. 9 is a flowchart showing an operation in the pointer display mode.The process flow indicated by this flowchart represents the operationexecuted when the data of pointer coordinates transmitted from thedisplay device 200 is received as described above.

When the communication unit 107 has received the data of pointercoordinates transmitted through the network 300, the display terminal100 stores the data of pointer coordinates in the memory 103 (stepS901). Then, it is determined whether the display terminal 100 is set tothe automatic magnification mode (step S902). When the display terminal100 is set to the automatic magnification mode, it is determined whetherthe display image 151 currently displayed on the display unit 102 is amagnified version of the display image 151 (step S903).

When it is determined at step S903 that the currently displayed displayimage 151 is not a magnified version of the display image 151 (forexample, normal display), the control unit 101 carries out the imageprocessing on the display data to create magnified image data anddisplays the magnified version of the display image 151 on the displayunit 102 (step S904). At this time, the magnification process is carriedout so that the pointer coordinates are located at the approximatecenter of the display image 151. Then, the pointer mark 150 is displayedat the position of the pointer coordinates in a superposed manner (stepS905), and the flow returns to the main operation process flow of FIG.6.

When it is determined at step S902 that the display terminal 100 is notset to the automatic magnification mode, the flow proceeds from stepS902 to step S905, and the pointer mark 150 is displayed at the positionof the pointer coordinates in a superposed manner, and the flow returnsto the main operation process flow of FIG. 6.

When it is determined at step S903 that the currently displayed displayimage 151 is a magnified version of the display image 151, the controlunit 101 creates image data having its approximate center correspondingto the pointer coordinates from the display data while maintaining thecurrent magnification scale, and displays the created image data on thedisplay unit 102 (step S906). Then, the pointer mark 150 is displayed atthe position of the pointer coordinates in a superposed manner (stepS905), and the flow returns to the main operation process flow of FIG.6.

As shown in FIG. 10( a), the display device 200 projects and displaysthe display image 251 (step S503 in FIG. 5), detects the positionpointed out by the pointer 260 (step S504 in FIG. 5), and displays thepointer mark 250 at the pointed out position in a superposed manner onthe display image 251 (step S506 in FIG. 5). Examples of image displayon the display terminal 100 at this time are shown in FIGS. 10( b) and10(c). FIG. 10( b) depicts an example in the case where the displayterminal 100 is set to the automatic magnification mode, and FIG. 10( c)depicts an example in the case where the display terminal 100 is not setto the automatic magnification mode.

When the display terminal 100 is set to the automatic magnificationmode, as shown in FIG. 10( b), a magnified version of the display image151 is displayed approximately around the pointer coordinates serving asthe center thereof (step S904 in FIG. 9), and the pointer mark 150 isdisplayed at the position of the pointer coordinates in a superposedmanner (step S905 in FIG. 9).

When the display terminal 100 is not set to the automatic magnificationmode, as shown in FIG. 10( c), the display data received from thedisplay terminal 100A serving as the host terminal is converted intoimage data (step S801 in FIG. 8), and the converted image data isdisplayed as the display image 151 (step S803 in FIG. 8), and thepointer mark 150 is displayed at the position of the pointer coordinatesin a superposed manner (step S905 in FIG. 9).

FIG. 10( d) depicts an example of image display in the case where theposition pointed out by the pointer 260 is shifted from that of FIG. 10(a). As shown in FIG. 10( d), the pointer mark 250 is displayed at ashifted position pointed out by the pointer 260 in a superposed manneron the display image 251. Examples of image display on the displayterminal 100 at this time are shown in FIGS. 10( e) and 10(f).

FIG. 10( e) depicts an example of image display in the case where thedisplay terminal 100 is set to the automatic magnification mode, andFIG. 10( f) depicts an example of image display in the case where thedisplay terminal 100 is not set to the automatic magnification mode.When the display terminal 100 is set to the automatic magnificationmode, since the image displayed on the display terminal 100 has alreadybeen magnified, as shown in FIG. 10(e), the image data having itsapproximate center corresponding to the pointer coordinates is createdand displayed while maintaining the magnification scale (step S906 inFIG. 9). Further, the pointer mark 150 is displayed at the position ofthe pointer coordinates in a superposed manner (step S905 in FIG. 9).

When the display terminal 100 is not set to the automatic magnificationmode, as shown in FIG. 10( f), the pointer mark 150 is displayed at theshifted position of the pointer coordinates (step S905 in FIG. 9).

When the overall display button 153 is selected in the states of FIGS.10( b) and 10(e) where a magnified version of the display image 151 isdisplayed, the whole of the display data is displayed as shown in FIGS.10( c) and 10(f). Also, when the magnifying button 154 is selected inthe states of FIGS. 10( c) and 10(f) where the whole of the display datais displayed as the display image 151, the display image 151 ismagnified around the pointer coordinates serving as the center thereofas shown in FIGS. 10( b) and 10(e).

As described above, by displaying the pointer mark 250 on the displayimage 251 projected and displayed by the display device 200 in asuperposed manner, the position pointed out by the pointer 260 can beindicated emphatically. Furthermore, since the position thereof (pointercoordinates) is transmitted to the display terminal 100 and the pointermark 150 is displayed also on the display image 151 of the displayterminal 100, the position pointed out by the pointer 260 can beconfirmed also on the display terminal 100.

Also, since the display data can be partially magnified and displayed onthe display terminal 100 having a screen smaller than the display image251, the user can check the details of the display contents.Furthermore, since the magnified image is displayed approximately aroundthe pointer coordinates serving as the center thereof, the part of theimage that the user of the display terminal 100 intends to see is alwaysdisplayed on the display unit 102, and this allows the user to check thedetails of the display contents without requirements of cumbersomeoperations.

Second Embodiment

Next, a display system 400 according to a second embodiment of thepresent invention will be described. Since the hardware configurationsof the display terminal 100 and the display device 200 are the same asthose of the first embodiment, the descriptions thereof will be omitted.The operations of the display terminal 100 and the display device 200 ofthe second embodiment are different from those of the first embodimentin the operation of the display terminal 100 in the pointer displaymode. In this embodiment, therefore, the pointer display mode of thedisplay terminal 100 will be described.

FIG. 11 is a flowchart of the operation in the pointer display mode. Theprocess indicated by this flowchart represents the operation carried outwhen the data of pointer coordinates transmitted from the display device200 is received.

When the communication unit 107 has received the data of pointercoordinates through the network 300, the data of pointer coordinates isstored in the memory 103 (step S1101). Then, it is determined whetherthe display terminal 100 is set to the automatic magnification mode(step S1102). When the display terminal 100 is set to the automaticmagnification mode, it is determined whether the display image 151currently displayed on the display unit 102 is a magnified version ofthe display image 151 (step S1103).

When it is determined at step S1103 that the currently displayed displayimage 151 is a magnified version of the display image 151 (for example,normal display), the control unit 101 carries out the image processingon the display data to create magnified image data, and the magnifiedversion of the display image 151 is displayed on the display unit 102(step S1104). At this time, the magnification process is carried out sothat the pointer coordinates are located at the approximate center ofthe display image 151. Then, the pointer mark 150 is displayed at theposition of the pointer coordinates in a superposed manner (step S1105),and the flow returns to the main operation process flow. When it isdetermined at step S1102 that the display terminal 100 is not set to theautomatic magnification mode, the pointer mark 150 is displayed at theposition of the pointer coordinates in a superposed manner (step S1105),and the flow returns to the main operation process flow.

When it is determined at step S1103 that the currently displayed displayimage 151 is a magnified version of the display image 151, it isdetermined whether the received pointer coordinates are within thedisplay area of the currently displayed display image 151 (step S1106).When it is determined that the pointer coordinates are within thedisplay area, the pointer mark 150 is displayed at the position of thepointer coordinates in a superposed manner without changing the displayimage 151 (step S1105), and the flow returns to the main operationprocess flow.

When it is determined at step S1106 that the pointer coordinates are notwithin the display area, the control unit 101 creates image data havingits approximate center corresponding to the pointer coordinates againwhile maintaining the current magnification scale, and displays thecreated image data on the display unit 102 (step S1107). Then, thepointer mark 150 is displayed at the position of the pointer coordinatesin a superposed manner (step S1105), and the flow returns to the mainoperation process flow.

FIG. 12 depicts examples of the display images 151 and 251 displayed onthe display terminal 100 and the display device 200. FIG. 12( a) depictsan example of image display of the display device 200, and this is thesame as FIG. 10( a) of the first embodiment, and therefore thedescription thereof will be omitted. An example of image display on thedisplay terminal 100 at this time is shown in FIG. 12( b). In FIG. 12(b), in the same manner as the display terminal 100 of the firstembodiment, a magnified version of the display image 151 is displayedapproximately around the position of the pointer coordinates serving asthe center thereof (step S1104 in FIG. 11), and the pointer mark 150 isdisplayed at the position of the pointer coordinates in a superposedmanner (step S1105 in FIG. 11).

FIG. 12( c) depicts an example of image display in the case where theposition pointed out by the pointer 260 is shifted from that of FIG. 12(a). As shown in FIG. 12( c), the pointer mark 250 is displayed at ashifted position pointed out by the pointer 260 in a superposed manneron the display image 251. As described above, when the amount of shiftof the pointer coordinates is so small that the shifted pointercoordinates are within the display area of the currently displayeddisplay image 151 (FIG. 12( b)), as shown in FIG. 12( d), the pointermark 150 is displayed at the shifted position of the pointer coordinatesin a superposed manner without changing the display image 151 (stepsS1106 to S1105 in FIG. 11).

FIG. 12( e) depicts an example of image display in the case where theposition pointed out by the pointer 260 is further shifted from theposition of FIG. 12( c). As shown in FIG. 12( e), the pointer mark 250is displayed at a shifted position pointed out by the pointer 260 in asuperposed manner on the display image 251. As described above, when theamount of shift of the pointer coordinates is so large that the shiftedpointer coordinates are not within the display area of the currentlydisplayed display image 151 (FIG. 12( b)), as shown in FIG. 12( f), theimage data having its approximate center corresponding to the pointercoordinates is created again as the display image 151 (step S1107 inFIG. 11), and the pointer mark 150 is displayed at the position of thepointer coordinates in a superposed manner (step S1105 in FIG. 11).

As described above, in the second embodiment, the same effect as thefirst embodiment can be achieved. Furthermore, in the display terminal,since the display image 151 is not changed when the pointer coordinatesare within the display area at the time of displaying a magnifiedversion of the image, the frequency of changes of the display image 151can be reduced, so that an effect of improving the easiness in checkingthe display data contents can be achieved.

Third Embodiment

Next, a display system 400 according to a third embodiment of thepresent invention will be described. Since the hardware configurationsof the display terminal 100 and the display device 200 are the same asthose of the first and second embodiments, the descriptions thereof willbe omitted. The operations of the display terminal 100 and the displaydevice 200 of the third embodiment are different from those of the firstand second embodiments in the operation of the display terminal 100 inthe pointer display mode. In this embodiment, therefore, the pointerdisplay mode of the display terminal 100 will be described.

FIG. 13 is a flowchart of the operation in the pointer display mode. Theprocess indicated by this flowchart represents the operation carried outwhen the data of pointer coordinates transmitted from the display device200 is received.

When the communication unit 107 has received the data of pointercoordinates through the network 300, the data of pointer coordinates isstored in the memory 103 (step S1301). Then, it is determined whetherthe display terminal 100 is set to the automatic magnification mode(step S1302). When the display terminal 100 is set to the automaticmagnification mode, it is determined whether the display image 151currently displayed on the display unit 102 is a magnified version ofthe display image 151 (step S1303).

When it is determined at step S1303 that the currently displayed displayimage 151 is a magnified version of the display image 151 (for example,normal display), the control unit 101 carries out the image processingon the display data to create magnified image data, and the magnifiedversion of the display image 151 is displayed on the display unit 102(step S1304). At this time, the magnification process is carried out sothat the pointer coordinates are located at the approximate center ofthe display image 151. Then, the pointer mark 150 is displayed at theposition of the pointer coordinates in a superposed manner (step S1305),and the flow returns to the main operation process flow.

When it is determined at step S1302 that the display terminal 100 is notset to the automatic magnification mode, the pointer mark 150 isdisplayed at the position of the pointer coordinates in a superposedmanner (step S1305), and the flow returns to the main operation processflow.

When it is determined at step S1303 that the currently displayed displayimage 151 is a magnified version of the display image 151, it isdetermined whether the received pointer coordinates are within thedisplay area of the currently displayed display image 151 (step S1306).When it is determined that the pointer coordinates are within thedisplay area, the pointer mark 150 is displayed at the position of thepointer coordinates in a superposed manner without changing the displayimage 151 (step S1305), and the flow returns to the main operationprocess flow.

When it is determined at step S1306 that the pointer coordinates are notwithin the display area, an out-of-area mark indicative of a positionout of the area is displayed in a superposed manner on the display image(step S1307). Next, it is determined whether the out-of-area mark isselected (step S1308). When it is determined that the out-of-area markis selected, the control unit 101 creates image data having itsapproximate center corresponding to the pointer coordinates again whilemaintaining the current magnification scale, and displays the createdimage data on the display unit 102 (step S1309). Then, the pointer mark150 is displayed at the position of the pointer coordinates in asuperposed manner (step S1305), and the flow returns to the mainoperation process flow.

When the out-of-area mark is not selected at step S1308, the pointermark 150 is deleted (step S1310), and the flow returns to the mainoperation process flow.

FIG. 14 depicts examples of the display images 151 and 251 displayed onthe display terminal 100 and the display device 200. FIG. 14( a) depictsan example of image display of the display device 200, and this is thesame as FIG. 10( a) of the first embodiment, and therefore thedescription thereof will be omitted. An example of image display on thedisplay terminal 100 at this time is shown in FIG. 14( b). In FIG. 14(b), in the same manner as the display terminal 100 of the firstembodiment, a magnified version of the display image 151 is displayedapproximately around the position of the pointer coordinates serving asthe center thereof (step S1304 in FIG. 13), and the pointer mark 150 isdisplayed at the position of the pointer coordinates in a superposedmanner (step S1305 in FIG. 13).

FIG. 14( c) depicts an example of image display in the case where theposition pointed out by the pointer 260 is shifted from that of FIG. 14(a). As shown in FIG. 14( c), this is the same as FIG. 12( c) of thesecond embodiment, and therefore, the description thereof will beomitted. As described above, when the amount of shift of the pointercoordinates is so small that the shifted pointer coordinates are withinthe display area of the currently displayed display image 151 (FIG. 14(b)), as shown in FIG. 14( d), the pointer mark 150 is displayed at theshifted position of the pointer coordinates in a superposed mannerwithout changing the display image 151 (steps 51306 to 51305 in FIG.13).

FIG. 14( e) depicts an example of image display in the case where theposition pointed out by the pointer 260 is further shifted from theposition of FIG. 14( c). As shown in FIG. 14( e), this is the same asFIG. 12( e) of the second embodiment, and therefore, the descriptionthereof will be omitted. As described above, when the amount of shift ofthe pointer coordinates is so large that the shifted pointer coordinatesare not within the display area of the currently displayed display image151 (FIG. 14( b)), as shown in FIG. 14( f), an out-of-area mark 155 isdisplayed without changing the display image 151 (step S1307 in FIG. 13)and the pointer mark 150 is deleted (step S1309 in FIG. 13).

In this state, when the out-of-area mark 155 is selected, image datahaving its approximate center corresponding to the pointer coordinatesis created again as the display image 151 (step S1310 in FIG. 13), andthe pointer mark 150 is displayed at the position of the pointercoordinates in a superposed manner (step S1305 in FIG. 13).

As described above, in the third embodiment, the same effect as thefirst and second embodiments can be achieved. Furthermore, in thedisplay terminal, the display image 151 is not changed if the pointercoordinates are within the display area when a magnified version of theimage is displayed.

Also, even if the pointer coordinates are out of the display area, thedisplay image 151 is not changed unless the user selects the out-of-areamark 155. Therefore, since the display image 151 is changed only at thetiming intended by the user, the effect of improving the easiness inchecking the display data contents can be achieved.

Furthermore, since the currently displayed image can be changed to thedisplay image 151 having its approximate center corresponding to thepointer coordinates 150 just by selecting the out-of-area mark 155, thehandiness in the third embodiment is not inferior to that achieved inthe first and second embodiments.

Fourth Embodiment

Next, a display system 400 according to a fourth embodiment of thepresent invention will be described. Since the hardware configurationsof the display terminal 100 and the display device 200 are the same asthose of the first to third embodiments, the descriptions thereof willbe omitted.

FIG. 15 is a flowchart showing an operation of the display device 200.It is presupposed that the process flow indicated by this flowchartstarts from a step of turning on a power supply. First, it is determinedwhether the communication unit 206 has received image data transmittedfrom a different device (display terminal 100A in this case) through thenetwork 300 (step S1501). When the communication unit 206 has failed toreceive image data, the flow proceeds to step S1504 to be describedlater. When the communication unit 206 has received image data at stepS1501, the image data is stored in the memory 204 (step S1502). Theimage data is subjected to image processing by the control unit 201, andthe display unit 202 then projects and displays the processed image dataon the screen 252 as the display image 251 (step S1503).

Subsequently, the sensor unit 203 detects a position (pointercoordinates) pointed out on the display image 251 by laser light emittedfrom the pointer 260 (step S1504). When the pointer position isdetected, the pointer coordinates representing the pointer position aretransmitted from the communication unit 206 to each display terminal 100through the network 300 (step S1505). The pointer mark 250 is thendisplayed on the display image 251 at the position corresponding to thepointer coordinates in a superposed manner (step S1506). After thepointer mark 250 is displayed, the flow returns to step S1501 andrepeats the process flow therefrom. Up to this step, the operation ofthe fourth embodiment is the same as that of the first embodiment.

When the position pointed out by the pointer 260 is not detected at stepS1504, it is determined whether data of the pointer coordinates isreceived from the display terminal 100. When having received the pointercoordinates, the pointer mark 250 is displayed at the positioncorresponding to the pointer coordinates in a superposed manner on thedisplay image 251 (step S1506), and the flow returns to step S1501 torepeat the process flow thereform. Also, when it is determined at stepS1507 that the pointer coordinates have not been received, the flowreturns to step S1501 to repeat the process flow thereform.

FIG. 16 is a flowchart of a main operation of the display terminal 100.It is presupposed that the process flow indicated by this flowchartstarts from a step of turning on a power supply. It is first determinedwhether a data selection mode is set (step S1601). When the dataselection mode is set, a process flow for the data selection mode iscarried out (step S1602). When it is determined at step S1601 that thedata selection mode is not set, the flow proceeds to step S1603.

Next, it is determined whether the communication unit 107 has receiveddisplay data from a different device (step S1603). When thecommunication unit 107 has received the display data, a process flow fora data display mode is carried out (step S1604). When it is determinedat step S1603 that the communication unit 107 has not received thedisplay data, the flow proceeds to step S1605.

Subsequently, it is determined whether the communication unit 107 hasreceived the data of pointer coordinates from a different device (stepS1605). When the communication unit 107 has received the data of pointercoordinates, a process flow for a pointer display mode is carried out(step S1606). When it is determined at step S1605 that the communicationunit 107 has not received the data of pointer coordinates, the flowproceeds to step S1607. Since the operations in the data selection mode,the data display mode, and the pointer display mode of the fourthembodiment are the same as those of the first to third embodiments, thedetailed descriptions thereof will be omitted.

Next, it is determined whether the display terminal 100 is set to thepointer transmission mode (step S1607). In this case, the displayterminal 100 is set to the pointer transmission mode by displaying apointer transmission mode button 156 on the display unit 102 andselecting the pointer transmission mode button 156. When it isdetermined that the display terminal 100 is in the pointer transmissionmode, a process flow for the pointer transmission mode is carried out(step S1608), and then the flow returns to the first step S1601.

The operation in the pointer transmission mode (step S1608) willhereinafter be described in detail.

FIG. 17 is a flowchart showing an operation in the pointer transmissionmode. First, it is determined whether the selection by a touch pen 160can be detected by the operation unit 104 (step S1701). When theselection cannot be detected, step S1701 is repeated. When the selectionby the touch pen 160 can be detected, position coordinates selected bythe touch pen 160 are calculated by the control unit 101 (step S1702).From the position coordinates selected by the touch pen 160 and themagnification scale, display area and others of the display image 151,pointer coordinates corresponding to the position coordinates on imagedata are calculated (step S1703) and are stored in the memory 103 (stepS1704).

Then, the pointer mark 150 is displayed at the position of the pointercoordinates on the display image 151 in a superposed manner (stepS1705). Next, data of the pointer coordinates is transmitted from thecommunication unit 107 to a different device (step S1706), and the flowreturns to the main operation process flow of FIG. 16.

FIG. 18 depicts examples of the display images 151 and 251 displayed onthe display terminal 100 and the display device 200. As shown in FIG.18( a), when the pointer transmission mode button 156 is displayed at agiven position on the display unit 102 and the pointer transmission modebutton 156 is selected, the display terminal 100 executes the operationfor the pointer transmission mode of FIG. 17. The details thereof willbe described below.

As shown in FIG. 18( a), when an arbitrary position on the display unit102 is selected by the touch pen 160 (step S1701 in FIG. 17), theoperation unit 104 detects the selected position and calculates itsposition coordinates on the display image 151 (step S1702). At thistime, when the display image 151 is displayed in its magnified form,pointer coordinates corresponding to the position coordinates on thedisplay data are calculated from the magnification scale and displayposition of the display image 151 (step 1703 in FIG. 17), and thepointer mark 150 is displayed at the position of the pointer coordinates(step 1705 in FIG. 17).

FIG. 18( b) is an example of the display image 251 projected anddisplayed by the display device 200. In FIG. 18( b), the pointer mark250 is displayed at the position of pointer coordinates transmitted fromthe display terminal 100 in a superposed manner on the display image 251(step 1506 in FIG. 15). FIGS. 18( c) and 18(d) are examples of imagedisplay on the display terminals 100 other than the display terminal 100of FIG. 18( a) on which a position of the display unit 102 is selectedby the touch pen 160. FIG. 18( c) depicts an example in which thepointer mark 150 is displayed on the display image 151 displayed as thewhole image, and FIG. 18( d) depicts an example in which the pointermark 150 is displayed on the display image 151 displayed as itsmagnified version.

As shown in FIG. 18, by giving different shapes to the pointer marks 150and 250 representing pointer coordinates transmitted from the displaydevice 200, it becomes possible to distinguish whether the displayedpointer marks 150 and 250 represent pointer coordinates transmitted fromthe display device 200 or pointer coordinates transmitted from thedisplay terminal 100. Also, the shapes of the pointer marks 150 and 250may be made different for each of the display terminals 100. In such acase, it is possible to distinguish which display terminal 100 thepointer coordinates are transmitted from.

As described above, in the fourth embodiment, the same effect as thefirst to third embodiments can be achieved. Furthermore, since aposition pointed out by the touch pen 160 on one display terminal 100can be confirmed on the display device 200 and the other displayterminals 100, the display system with improved handiness can berealized.

Fifth Embodiment

Next, a display system 400 according to a fifth embodiment of thepresent invention will be described. Since the hardware configurationsof the display terminal 100 and the display device 200 are the same asthose of the first to fourth embodiments, the descriptions thereof willbe omitted.

FIG. 19 depicts examples of the display images 151 and 251 displayed onthe display terminal 100 and the display device 200. As shown in FIG.19( a), when the pointer 260 pointing out a position is moved on thedisplay image 251 projected and displayed by the display device 200, thepointer mark 250 is displayed together with a pointer mark track 257.The pointer mark track 257 can be drawn by connecting the currentpointer coordinates and the previous pointer coordinates by a linesegment.

Examples of display of the display image 151 on the display terminal 100at this time are shown in FIGS. 19( b) and 19(c). FIG. 19( b) depictsthe case where the display image 151 is displayed as the whole image,and FIG. 19( c) depicts the case where the display image 151 isdisplayed as its magnified version. Also on the display terminal 100,the pointer mark 150 is displayed together with a pointer mark track 157in the same manner as on the display device 200. The pointer mark track157 is drawn by connecting the current pointer coordinates and theprevious pointer coordinates by a line segment.

When the display terminal 100 is set to the automatic magnificationmode, magnified image display is controlled so that the approximatecenter of the pointer mark track 157 is located at the center of thedisplay image as shown in FIG. 19( c). Note that, though not shown, themagnified image display may be controlled so that the position of thepointer mark 150 is located at the approximate center of the displayimage.

Also, in the description above, the pointer mark track 157 is created inthe display terminal 100, but the present invention is not limited tothis. For example, it is also possible to create the data of the pointermark track 257 in the display device 200, transmit the data to thedisplay terminal 100, and then display the pointer mark track 157 basedon the pointer mark track data.

As described above, in the fifth embodiment, the same effect as thefirst to fourth embodiments can be achieved. Furthermore, since thetrack of the position pointed out by the pointer 260 can be confirmed onthe display device and all display terminals, the display system withimproved handiness can be realized.

Sixth Embodiment

Next, a display system 400 according to a sixth embodiment of thepresent invention will be described. Since the hardware configurationsof the display terminal 100 and the display device 200 are the same asthose of the first to fifth embodiments, the descriptions thereof willbe omitted.

FIG. 20 depicts examples of the display images 151 and 251 displayed onthe display terminal 100 and the display device 200. As shown in FIG.20( a), when the touch pen 160 is moved on the display image 151 on thedisplay terminal 100 while touching the screen, the pointer mark 150 isdisplayed together with a pointer mark track 157.

In the same manner as the fifth embodiment, the pointer mark track 157can be drawn by connecting the current pointer coordinates and theprevious pointer coordinates by a line segment. An example of display ofthe display image 251 on the display device 200 at this time is shown inFIGS. 20( b).

As shown in FIG. 20( b), also on the display image 251 projected anddisplayed by the display device 200, the pointer mark 250 is displayedtogether with the pointer mark track 257. The pointer mark track 257 canbe similarly drawn by connecting the current pointer coordinates and theprevious pointer coordinates by a line segment.

Examples of display of the display image 151 on the other displayterminals 100 are shown in FIGS. 20( c), 20(d), and 20(e). On all of thedisplay terminals 100, the pointer mark 150 is displayed together withthe pointer mark track 157. FIG. 20( c) depicts the case where thedisplay image 151 is displayed as the whole image, and FIG. 20( d) andFIG. 20( e) depict the case where the display image 151 is displayed asits magnified version. In FIG. 20( d), the same display area as thedisplay area of the display terminal 100 (FIG. 20( a)) operated with thetouch pen 160 is displayed.

This can be realized by transmitting data of the magnification scale anddisplay position together to the other devices when the display terminal100 transmits the data of pointer coordinates. The other display device100 which has received the data can determine the form of display of thedisplay image 151 based on the received data of the magnification scaleand display position.

Also, as shown in FIG. 20( e), the magnified image display may becontrolled so that the approximate center of the pointer mark track 157is located at the center of the display image. Note that, though notshown, the magnified image display may be controlled so that theposition of the pointer mark 150 is located at the approximate center ofthe display image.

Also, in the description above, the pointer mark track 257 is created inthe display device 200, but the present invention is not limited tothis. For example, it is also possible to create the data of the pointermark track 157 in the display terminal 100 operated with the touch pen160, transmit the data to the display device 200, and then display thepointer mark track 257 based on the pointer mark track data.

Similarly, the display terminals 100 other than the display terminal 100operated with the touch pen 160 may receive the pointer mark track dataand display the pointer mark track 157.

Also, in the same manner as the fourth embodiment, by giving differentshapes to the pointer marks 150 and 250 representing pointer coordinatestransmitted from the display device 200, it becomes possible todistinguish whether the displayed pointer marks 150 and 250 representpointer coordinates transmitted from the display device 200 or pointercoordinates transmitted from the display terminal 100.

Furthermore, in the same manner as the fourth embodiment, the shapes ofthe pointer marks 150 and 250 may be made different for each of thedisplay terminals 100. In such a case, it is possible to distinguishwhich display terminal 100 the pointer coordinates are transmitted from.

As described above, in the sixth embodiment, the same effect as thefirst to fifth embodiments can be achieved. Furthermore, since the trackof the operation of the touch pen 160 can be confirmed on the displaydevice and all display terminals, the display system with improvedhandiness can be realized.

Seventh Embodiment

Next, a display system 400 according to a seventh embodiment of thepresent invention will be described. Since the hardware configurationsof the display terminal 100 and the display device 200 are the same asthose of the first to fifth embodiments, the descriptions thereof willbe omitted.

FIG. 21 depicts examples of the display images 151 and 251 displayed onthe display terminal 100 and the display device 200.

As shown in FIG. 21( a), a magnified version of the display image 251 isdisplayed on the display device 200. This magnified display image 251 isprojected and displayed on the display unit 202 through themagnification process of image data by the control unit 201 instructedby the user operation to the operation unit 205 of the display device200.

At this time, the display device 200 transmits data of the magnificationscale and display position to the display terminal 100 through thecommunication unit 206. At this time, the display terminal 100 displaysthe display image 151 magnified in the same manner as the display image251 as shown in FIG. 21( b). In this case, the control unit 101 createsmagnified image data by using the display data and the data of themagnification scale and display position received from the displaydevice 200 so that the display image 151 almost identical to the displayimage 251 is formed, and the created image data is displayed on thedisplay unit 102 as the display image 151.

As shown in FIG. 21( c), also when a position is pointed out by thepointer 260 on the magnified display image 251, the pointer mark 250 issimilarly displayed. At this time, the pointer mark 150 is displayed onthe display terminal 100 as shown in FIG. 21( d).

As described above, by transmitting and receiving the data of themagnification scale and display position so as to share the data betweenthe display terminal 100 and the display device 200, when the displaydevice 200 displays the magnified display image 251, the displayterminal 100 can display the image corresponding to the magnifieddisplay image 251.

In the description above, a magnified version of the display image 251is displayed by the operation on the operation unit 205 of the displaydevice 200, but the present invention is not limited to this. Forexample, a magnified version of the display image 251 may be displayedby transmitting a magnification display instruction from the displayterminal 100 to the display device 200.

As described above, in the seventh embodiment, the same effect as thefirst to sixth embodiments can be achieved. Furthermore, when thedisplay device 200 displays a magnified version of the display image251, the display terminal 100 similarly displays the magnified displayimage, so that the display system with improved handiness can berealized.

Note that, in the description of the display system 400 of the first toseventh embodiments, the case of using the wireless LAN for thecommunication with the network 300 has been described, but the presentinvention is not limited to this. For example, it is also possible tomake the communication based on other communication methods such asW-CDMA (Wideband Code Division Multiple Access) and GSM (Global Systemfor Mobile Communications (registered trademark)) through a base station(not depicted).

In this case, even when a user is in a remote place, the user is able toparticipate in a meeting or the like in which the display device 200 isused as long as the user is within a range of communication with thebase station. At this time, audio signals input to the sound input unit208 of the display device 200 are transmitted to each display terminal100 and are output from the sound output unit 110 of the displayterminal 100. Obviously, communication through Bluetooth (registeredtrademark) or wired LAN is also applicable.

Also, the display terminal 100A serving as the host terminal and thedisplay device 200 transmit and receive image data through the network300, but the present invention is not limited to this. For example,example, it is also possible to connect the connection unit 108A of thedisplay terminal 100A and the connection unit 207 of the display device200 via a connection cable (not depicted) and to transmit and receivethe image data through the connection cable.

Also, in the case of the wired connection by the connection cablementioned above, it is not always necessary to provide the communicationunit 206. At this time, the data of pointer coordinates is transmittedto the display terminal 100A through the connection cable, and thedisplay terminal 100A transmits the data of pointer coordinates to theother display terminals 100B and 100C.

Also, in the description above, the display device 200 is provided withthe sensor unit that detects a position pointed out by the pointer 260,but the present invention is not limited to this, and the sensor unitmay be provided separately from the display device 200.

Also, in the description above, the display unit 202 of the displaydevice 200 is a projector, but the present invention is not limited tothis. For example, the display unit 202 may be a liquid crystal panel,plasma display panel, organic EL, and others.

Also, in the description above, the pointer 260 emits optical light froma remote place to point out an arbitrary position like a laser pointer,but the present invention is not limited to this, and the pointer 260may be a pointer rod, touch pen, and others.

Also, in the description above, the sensor unit 203 takes a displayimage like a camera and detects pointer coordinates, but the presentinvention is not limited to this. For example, the sensor unit maydetect a position pointed out by the pointer 206 by receiving signalssuch as ultrasonic waves, infrared light and others output from thepointer 260 at multiple spots and calculating the distance between thesensor unit and the pointer 260.

Also, the sensor unit 203 may be a touch panel or the like that detectsa direct touch onto the display image 251.

Some or the whole of the configurations, functions, processing units,processing means and others mentioned above may be realized in the formof hardware by designing them with, for example, integrated circuits.Alternatively, the above-mentioned configurations, functions and thelike may be realized by software by, for example, allowingmicroprocessor units to interpret and execute the programs for realizingthe respective functions. Programs for realizing the respectivefunctions may be stored in advance in a memory, storage, and others, ormay be downloaded afterward from an external application server into amemory, storage, and others.

DESCRIPTION OF REFERENCE CHARACTERS

-   100 Display terminal-   102 Display unit-   150 Pointer mark-   151 Display image-   157 Pointer mark track-   160 Touch pen-   200 Display device-   250 Pointer mark-   251 Display image-   257 Pointer mark track-   260 Pointer-   300 Network-   400 Display system

1. A display system comprising: a display terminal that displays firstimage data; and a display device that displays second image data inconjunction with the display terminal, wherein display contents of thefirst image data include contents of a partial area of display contentsof the second image data, and a pointer mark of the display terminal isdisplayed at an image position of the first image data that correspondsto an image position of the second image data at which a pointer mark ofthe display device is displayed.
 2. The display system according toclaim 1, wherein, when the image position of the pointer mark displayedon the display device is shifted, the first image data displayed on thedisplay terminal is changed.
 3. A display system comprising: a displayterminal; and a display device, wherein the display terminal displaysgiven image data, the display terminal transmits the image data to thedisplay device, the display device displays received image data, thedisplay device detects position coordinates pointed out by a pointer ona displayed image, the display device displays a given pointer mark at aposition corresponding to the detected position coordinates, the displaydevice transmits the detected position coordinates to the displayterminal, and the display terminal displays a given pointer mark at aposition corresponding to the position coordinates.
 4. The displaysystem according to claim 3, wherein the display terminal displays amagnified version of an image.
 5. The display system according to claim3, wherein the display terminal displays a magnified version of an imageapproximately around the received position coordinates serving as acenter thereof.
 6. The display system according to claim 3, wherein thedisplay terminal displays a magnified version of an image so that thereceived position coordinates are always located at an approximatecenter of the image.
 7. The display system according to claim 3,wherein, when the received position coordinates are out of an area of adisplay image displayed on a display unit, the display terminal displaysa magnified version of the display image so that the received positioncoordinates are located at an approximate center of the image.
 8. Thedisplay system according to claim 3, wherein, when the received positioncoordinates are out of an area of a display image displayed on a displayunit, the display terminal displays a given mark.
 9. The display systemaccording to claim 8, wherein the display terminal displays a magnifiedversion of a display image approximately around the received positioncoordinates serving as a center thereof by carrying out a givenoperation.
 10. A display terminal comprising: a control unit; a displayunit; and a communication unit, wherein a display image is displayed onthe display unit, and a given pointer mark is displayed at a positioncorresponding to received position coordinates.
 11. The display terminalaccording to claim 10, wherein a magnified version of a display image isdisplayed.
 12. The display terminal according to claim 10, wherein amagnified version of a display image is displayed approximately aroundthe received position coordinates serving as a center thereof.
 13. Thedisplay terminal according to claim 10, wherein a magnified version ofan image is displayed so that the received position coordinates arealways located at an approximate center of the image.
 14. The displayterminal according to claim 10, wherein, when the received positioncoordinates are out of an area of the display image displayed on thedisplay unit, a magnified version of the display image is displayed sothat the received position coordinates are located at an approximatecenter of the image.
 15. The display terminal according to claim 10,wherein, when the received position coordinates are out of an area ofthe display image displayed on the display unit, a given mark isdisplayed.
 16. The display terminal according to claim 15, wherein amagnified version of the display image is displayed approximately aroundthe received position coordinates serving as a center thereof bycarrying out a given operation.
 17. A display device comprising: acontrol unit; a display unit; a communication unit; and a sensor unit,wherein the display unit displays image data, the sensor unit detectsposition coordinates pointed out by a pointer on a displayed image, thecommunication unit transmits the detected position coordinates, and agiven pointer mark is displayed at the position coordinates.
 18. Adisplay method of a display terminal, comprising the steps of:displaying a display image on a display unit; displaying a given pointermark at a position corresponding to received position coordinates; anddisplaying a magnified version of the display image approximately aroundthe received position coordinates serving as a center thereof.
 19. Acontrol program that can be executed by a display terminal, whichdisplays a display image on a display unit, displays a given pointermark at a position corresponding to received position coordinates, anddisplays a magnified version of the display image approximately aroundthe received position coordinates serving as a center thereof.